This invention relates to a method for the detection and measurement of concentrations for minor elements, especially non-metallic and semi-metallic elements, in molten metallurgical phases, e.g. metals, alloys, slags, matters and drosses.
There is a need, especially in metal refining and alloying processes, for a method to monitor the concentrations of minor elements in the melts as the process proceeds, so that the process can be controlled.
UK patent Nos. GB-A-1,470,558 (corresponding to U.S. Pat. No. 4,166,009) and 1,602,564 describe and claim electrolytic sensors for such purposes, wherein a solid electrolyte, based on a .beta.-alumina matrix, is interposed between the melt being tested and the elements to be detected or measured. However, the ionic species which can be measured by this prior method are limited to ions which are mobile in the solid electrolyte, i.e. monovalent and some divalent and trivalent ions such as alkali metal/alkaline earth metal ions.
There is a problem where detection or measurement of multi-valent elements such as P, As, Sb, S or Si in metallurgical phases is required, as it may be in many refining or alloying processes.
The present invention therefore seeks to meet this requirement and provide a method which overcomes the disadvantages of the prior art.